Near Net Shape High Pressure Molding

Near Net Shapes for High Performance Polymers

Piper Plastics has developed a proprietary high pressure molding technology that yields near net shape polymers up to 2" thick without porosity, voids or sinks. The process, which utilizes molding equipment designed and developed by Piper Plastics, allows the company to mold high performance thermoplastics, filled or unfilled, with isotropic mechanical properties.


Consistent Mechanical Properties
Near net shape high pressure molding is especially beneficial for large CNC machined parts that were historically limited to extruded or compression molded stock shapes. In comparison to extrusion and compression molding, this new process yields parts that have higher strength - typically 15-20% stronger than extruded shapes, and 50% stronger than compression molded shapes - plus more consistent mechanical properties.

Finished semiconductor part machined from a white ceramic-filled PEEK near net shape.

Metal (aluminum) replacement: aerospace bulkhead pass-through machined from carbon-filled PEEK near net shape.

Lower Machining Costs
A major reason for developing the new technology was to save costs when machining finished parts from expensive high performance materials such as PEEK, PAI or TPI. Since the molds are inexpensive, the low tolerance near net shape will be machined after molding. Because it is so close to the final part, a near net shape requires less machining. Less machining means less waste - an important consideration for green and sustainable programs.

Small Batch Runs
The near net technology allows Piper to offer small batch runs for mating the right polymer or blend for an application. Distributors typically only carry about 50 types of engineering plastics but with this technology Piper can mold custom blanks from over 3,000 polymers and compounds, or develop a compound specifically for an application.

Larger Part Sizes and Weights
The near net process is suitable for larger parts and weights of up to 6 pounds per blank with large and varying wall thicknesses and complex geometries. Near net shapes are effective for parts that cannot be produced using standard injection molding because the cross sectional area is too thick.

Targeted Industries
  • Aerospace
  • Industrial
  • Food Processing
  • Recreation
  • Medical
  • Oil & Gas
  • Chemical
  • Semiconductor/Electronics
Potential Applications
  • Brackets
  • Rings, Seals, Gaskets
  • Aircraft Manhole Covers
  • Aircraft Seat Structures
  • Clamps
  • Bearings, Bushings
  • Medical Equipment Manifolds
  • Semiconductor Rings


Near Net Shape High Performance Resins

The following are high performance resins that are used in Piper Plastics near net shape high pressure molding: PEEK, PEI, PAI, PPS, PEK, TPI, and carbon filled high strength polymers.


Design Requirements

  • Flexural modulus - 1,000,000 psi
  • Tensile strength - 25,000 psi
  • Good impact strength
  • Density: 1.35 g/cm3 or less
  • Cost effective compared to aluminum
  • The component has a thin cross section machined in the center of the part so property loss in the internal regions was not prohibited.


The near net shape high pressure molded brackets were 10” wide x 1.25” thick with center regions 0.06” thick and exhibited 0% porosity on loss of properties in the internal region.

As a subsidiary of Quadrant Engineering Plastic Products, Piper near net shapes are now also available from all authorized Quadrant distributors.

For more information on Piper’s Near Net Shape high pressure molding, please email